Field
This disclosure relates generally to communications and more specifically to an antenna system for near-field magnetic induction wireless communications.
Related Art
Near-field magnetic induction (NFMI) wireless communication utilizes non-propagating quasi-static fields. The quasi-static characteristic of the field is the result of antenna dimensions in combination with the carrier frequency. The majority of the energy is stored in the form of magnetic and electric fields and a small amount of radio frequency (RF) energy propagates in free space. Because NFMI does not depend on generating radiating waves in free space, small antenna geometries compared with the carrier wavelength can be used. The antenna can be a coil antenna that allows NFMI.
Implementation in small applications like earbuds or smart watches require very small antenna constructions that reduce the robustness of the wireless communication link between transmitter and receiver. Therefore, a need exists for a NFMI antenna that can be integrated in very small wireless products near to the human body and that will provide good reliability for wireless communication while also being energy efficient.